Replace c/b/nss_context by a KeyedService.

chromeos/tpm_token_loader.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROMEOS_TPM_TOKEN_LOADER_H_
 #define CHROMEOS_TPM_TOKEN_LOADER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 14 matching lines @@
 
 // This class is responsible for loading the TPM backed token for the system
 // slot when the user logs in. It is expected to be constructed on the UI thread
 // and public methods should all be called from the UI thread.
 // When the TPM token is loaded, or if the TPM should stay disabled for the
 // session, the observers are notified using |OnTPMTokenReady|.
 // Note: This currently initializes the token with the hard coded default id 0.
 // See CryptohomeClient::OnPkcs11GetTpmTokenInfo.
 class CHROMEOS_EXPORT TPMTokenLoader : public LoginState::Observer {
  public:
-  class Observer {
-   public:
-    // Called when the TPM token initialization is done or the case where TPM
-    // should stay disabled is detected (e.g. on guest login).
-    virtual void OnTPMTokenReady() = 0;
+  enum TPMTokenStatus {
+    TPM_TOKEN_STATUS_UNDETERMINED,
+    TPM_TOKEN_STATUS_ENABLED,
+    TPM_TOKEN_STATUS_DISABLED
+  };
 
-   protected:
-    virtual ~Observer() {}
-  };
+  typedef base::Callback<void(bool)> TPMReadyCallback;
+  typedef std::vector<TPMReadyCallback> TPMReadyCallbackList;
 
   // Sets the global instance. Must be called before any calls to Get().
   // The global instance will immediately start observing |LoginState|.
   static void Initialize();
 
   // Sets the global. stubbed out, instance. To be used in tests.
   static void InitializeForTest();
 
   // Destroys the global instance.
   static void Shutdown();
 
   // Gets the global instance. Initialize() must be called before this.
   static TPMTokenLoader* Get();
 
   // Returns true if the global instance has been initialized.
   static bool IsInitialized();
 
   // |crypto_task_runner| is the task runner that any synchronous crypto calls
   // should be made from, e.g. in Chrome this is the IO thread. Must be called
   // after the thread is started. When called, this will attempt to start TPM
   // token loading.
   void SetCryptoTaskRunner(
       const scoped_refptr<base::SequencedTaskRunner>& crypto_task_runner);
 
-  void AddObserver(TPMTokenLoader::Observer* observer);
-  void RemoveObserver(TPMTokenLoader::Observer* observer);
-
-  // Checks if the TPM token in ready to be used.
-  bool IsTPMTokenReady() const;
+  // Checks if the TPM token is enabled. If the state is unknown, |callback|
+  // will be called back once the TPM state is known.
+  TPMTokenStatus IsTPMTokenEnabled(const TPMReadyCallback& callback);
 
   std::string tpm_user_pin() const { return tpm_user_pin_; }
 
  private:
   explicit TPMTokenLoader(bool for_test);
   virtual ~TPMTokenLoader();
 
+  bool IsTPMLoadingEnabled() const;
+
   // Starts tpm token initialization if the user is logged in and the crypto
   // task runner is set.
   void MaybeStartTokenInitialization();
 
   // This is the cyclic chain of callbacks to initialize the TPM token.
   void ContinueTokenInitialization();
   void OnTPMTokenEnabledForNSS();
   void OnTpmIsEnabled(DBusMethodCallStatus call_status,
                       bool tpm_is_enabled);
   void OnPkcs11IsTpmTokenReady(DBusMethodCallStatus call_status,
                                bool is_tpm_token_ready);
   void OnPkcs11GetTpmTokenInfo(DBusMethodCallStatus call_status,
                                const std::string& token_name,
                                const std::string& user_pin,
                                int token_slot_id);
   void OnTPMTokenInitialized(bool success);
 
   // If token initialization step fails (e.g. if tpm token is not yet ready)
   // schedules the initialization step retry attempt after a timeout.
   void RetryTokenInitializationLater();
 
   // Notifies observers that the TPM token is ready.
   void NotifyTPMTokenReady();
 
   // LoginState::Observer
   virtual void LoggedInStateChanged() OVERRIDE;
 
   bool initialized_for_test_;
 
-  ObserverList<Observer> observers_;
+  TPMReadyCallbackList tpm_ready_callback_list_;
 
   // The states are traversed in this order but some might get omitted or never
   // be left.
   enum TPMTokenState {
     TPM_STATE_UNKNOWN,
     TPM_INITIALIZATION_STARTED,
     TPM_TOKEN_ENABLED_FOR_NSS,
     TPM_DISABLED,
     TPM_ENABLED,
     TPM_TOKEN_READY,
@@ skipping 16 matching lines @@
   scoped_refptr<base::SequencedTaskRunner> crypto_task_runner_;
 
   base::WeakPtrFactory<TPMTokenLoader> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TPMTokenLoader);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_TPM_TOKEN_LOADER_H_